1 /*
2  * Misc. bootloader code for many machines.
3  *
4  * Copyright 2001 MontaVista Software Inc.
5  * Author: Matt Porter <mporter@mvista.com> Derived from
6  * arch/ppc/boot/prep/misc.c
7  *
8  * Copyright (C) 2009 Lemote, Inc. & Institute of Computing Technology
9  * Author: Wu Zhangjin <wuzj@lemote.com>
10  *
11  * This program is free software; you can redistribute  it and/or modify it
12  * under  the terms of  the GNU General  Public License as published by the
13  * Free Software Foundation;  either version 2 of the  License, or (at your
14  * option) any later version.
15  */
16 
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 
20 #include <asm/addrspace.h>
21 
22 /* These two variables specify the free mem region
23  * that can be used for temporary malloc area
24  */
25 unsigned long free_mem_ptr;
26 unsigned long free_mem_end_ptr;
27 char *zimage_start;
28 
29 /* The linker tells us where the image is. */
30 extern unsigned char __image_begin, __image_end;
31 extern unsigned char __ramdisk_begin, __ramdisk_end;
32 unsigned long initrd_size;
33 
34 /* debug interfaces  */
35 extern void puts(const char *s);
36 extern void puthex(unsigned long long val);
37 
38 void error(char *x)
39 {
40 	puts("\n\n");
41 	puts(x);
42 	puts("\n\n -- System halted");
43 
44 	while (1)
45 		;	/* Halt */
46 }
47 
48 /* activate the code for pre-boot environment */
49 #define STATIC static
50 
51 #ifdef CONFIG_KERNEL_GZIP
52 void *memcpy(void *dest, const void *src, size_t n)
53 {
54 	int i;
55 	const char *s = src;
56 	char *d = dest;
57 
58 	for (i = 0; i < n; i++)
59 		d[i] = s[i];
60 	return dest;
61 }
62 #include "../../../../lib/decompress_inflate.c"
63 #endif
64 
65 #ifdef CONFIG_KERNEL_BZIP2
66 void *memset(void *s, int c, size_t n)
67 {
68 	int i;
69 	char *ss = s;
70 
71 	for (i = 0; i < n; i++)
72 		ss[i] = c;
73 	return s;
74 }
75 #include "../../../../lib/decompress_bunzip2.c"
76 #endif
77 
78 #ifdef CONFIG_KERNEL_LZMA
79 #include "../../../../lib/decompress_unlzma.c"
80 #endif
81 
82 void decompress_kernel(unsigned long boot_heap_start)
83 {
84 	int zimage_size;
85 
86 	/*
87 	 * We link ourself to an arbitrary low address.  When we run, we
88 	 * relocate outself to that address.  __image_beign points to
89 	 * the part of the image where the zImage is. -- Tom
90 	 */
91 	zimage_start = (char *)(unsigned long)(&__image_begin);
92 	zimage_size = (unsigned long)(&__image_end) -
93 	    (unsigned long)(&__image_begin);
94 
95 	/*
96 	 * The zImage and initrd will be between start and _end, so they've
97 	 * already been moved once.  We're good to go now. -- Tom
98 	 */
99 	puts("zimage at:     ");
100 	puthex((unsigned long)zimage_start);
101 	puts(" ");
102 	puthex((unsigned long)(zimage_size + zimage_start));
103 	puts("\n");
104 
105 	if (initrd_size) {
106 		puts("initrd at:     ");
107 		puthex((unsigned long)(&__ramdisk_begin));
108 		puts(" ");
109 		puthex((unsigned long)(&__ramdisk_end));
110 		puts("\n");
111 	}
112 
113 	/* this area are prepared for mallocing when decompressing */
114 	free_mem_ptr = boot_heap_start;
115 	free_mem_end_ptr = boot_heap_start + BOOT_HEAP_SIZE;
116 
117 	/* Display standard Linux/MIPS boot prompt for kernel args */
118 	puts("Uncompressing Linux at load address ");
119 	puthex(VMLINUX_LOAD_ADDRESS_ULL);
120 	puts("\n");
121 	/* Decompress the kernel with according algorithm */
122 	decompress(zimage_start, zimage_size, 0, 0,
123 		   (void *)VMLINUX_LOAD_ADDRESS_ULL, 0, error);
124 	/* FIXME: is there a need to flush cache here? */
125 	puts("Now, booting the kernel...\n");
126 }
127